The present inventive concept generally relates to the field of electronics and, more particularly, an image sensor.
An image sensor is a sensor that converts an optical image into an electric signal. Recently, with the development of the computer industry and the communication industry, there has been an increasing demand for an image sensor with improved performance in various fields such as a digital camera, a camcorder, a personal communication system (PCS), a game device, a security camera and a medical micro camera.
The image sensor may be classified into, for example, a charge coupled device (CCD) image sensor and a CMOS image sensor. In the CMOS image sensor, a simple driving scheme may be used, and signal processing circuits may be integrated into a single chip, thereby realizing miniaturization of a product. Also, the CMOS image sensor may have very low power consumption, and thus, may be easily applied to a product with limited battery capacity. In addition, the manufacturing cost may be reduced by using compatible CMOS process technology. Therefore, the CMOS image sensor is rapidly increasing in use as high resolution may be realized along with technology development.
As semiconductor devices have become highly integrated, image sensors have also become highly integrated. Accordingly, a sharing structure that may include a plurality of pixels constituting one unit pixel and one unit pixel sharing pixel transistors may be beneficial.